Patent GB-315802-A (GB)
IPC: H02J13/00
Filed: 1929-07-18
Abstract: 315,802. Associated Electrical Xndustries, Ltd., (Assignees of Wensley, R., J.). July 18, 1928, [Convention date]. Selective distant control systems; tell-tale apparatus.-In a system for selectively operating and supervising from a control station apparatus units, such as circuit-breakers, at a plurality of substations, the. apparatus units are adapted to be operated by mechanical energy storage devices,. such as springs, which may be selectively released to cause operation of the unit. The use of the storage devices avoids the use of batteries at the substations. As shown, circuit-breakers 8, 9 located at stations 2, 3 respectively are adapted to be selected by stepping switches 29, which are operated over the line wires 31, 70 by impulses of positive polarity transmitted by the impulse sender 32. Operation of a selected circuit-breaker is effected by an impulse of negative polarity transmitted by the sender 33 to one or other of the polarized relays 25, 26 depending upon the nature of the operation to be effected to cause release of the mechanical energy storing device 10, 11, 18 and operation of the circuitbreaker. When a unit changes position an impulse is transmitted over the line wire 46 and the contacts of a stepping switch 37 which is operated synchronously with the selecting switches 39 to operate the appropriate relay of the pair 40, 41 and the corresponding lamp 38 or 39. In the event of the automatic operation of a unit when the stepping switches are in their normal positions the line circuit 46 is opened momentarily to de-energize relay 44 and cause operation of alarm 55, which can only be nullified by depression of the key 57. Apparatus unit operating arrangements. Each circuit-breaker is connected through worm gearing 15, 16 to a shaft 14 which is coupled to the shaft of an electric motor 10 by a spring 11. The motor 10 is supplied from the mains and winds the spring 11 to a degree which is sufficient to cause operation of the circuit-breaker. The spring controls contacts 12 in such a manner that when the spring is wound the motor circuit is opened, but when unwound the contacts 12 are closed to cause the motor to rewind the spring. A disc 18 on the shaft 17 of the circuit-breaker has projections 19, 20 which are adapted to cooperate with the latch armatures 21, 22 of the polarized relays 25, 26. In the arrangement shown energization of the relay 25 disengages the latch 21 from the projection 19 and permits rotation of the shaft 17 through a quarter of the revolution until the projection engages the latch 22,. when the circuit-breaker is maintained in the closed position. Similarly, operation of relay 26 permits rotation of the shaft until projection 20 engages the latch 21 and the circuit-breaker is again opened. A ratchet is provided to prevent reverse rotation of the motor when its circuit is opened. Selective control of a circuit-breaker. To select any particular circuit-breaker the appropriate number of positive impulses are transmitted over the line wires 31, 70 to operate the stepping magnets 30 of the selector switches 29 and the stepping magnet 36 of the supervisory switch 37 in a series circuit. One or other of the polarized relays 25, 26 associated with the selected unit is thereby connected over the contacts of the corresponding selector to the line 31, the stepping circuit of the other selectors being completed through the relay, which however remains inoperative owing to its polarity. The appropriate relay is then operated by a negative impulse transmitted by the sender 33 to cause operation of the circuit-breaker. Supervision. When the unit changes its position a circuit is closed over the auxiliary switch 60 of the circuit-breaker and selectors 37, 39 through the line 46 for one or other of the relays 40, 41 to cause illumination of the corresponding signal lamp 38 or 39. The operated relay locks up and also opens the locking circuit of the other relay of the pair. If the selectors are at normal a relay 44 is energized in a series-circuit over line 46 and the auxiliary contacts 50 of all the circuit-breakers. In the event of a unit operating automatically, the series circuit is opened momentarily at the contact 50 and the relay 44 is de-energized to operate relay 42 which prepares the current of relay 43. When relay 44 is again energized relay 43 locks up in series with relay 42 over a nullifying key 57 and also operates an alarm 55. The dial switch 32 is then operated to step the selecting switches until a change of indication of the supervisory lamps is effected to apprise the operator of the affected circuitbreaker.